Multilateral wells typically have one or more secondary wellbores, often referred to as branch or lateral wellbores, extending from a primary wellbore, often referred to as a main or parent wellbore. The intersection between a primary wellbore and a secondary wellbore is often referred to as a wellbore junction. Completion equipment positioned at a wellbore junction for controlling fluid communication between the secondary wellbore, the downstream portion of the primary wellbore and the upstream portion of the primary wellbore may also be referred to as a junction. Such fluid communication may involve flow from the well, such as in the case of the production of hydrocarbons from the various wellbores, or may involve flow into the well, such as reservoir stimulation or fracturing during well intervention operations.
Various completion technologies for wellbore junctions provide for fluid communication between a primary and a secondary wellbore, but do not readily permit the flow (either into or out of) each of the wellbores to be varied or combined. Other completion technologies for wellbore junctions provide for varying the rate of fluid flow into or out of a wellbore, but do not permit fluid flow between the wellbores. In certain instances, the entire completion string must be retrieved from the well to establish fluid communication with a secondary wellbore, or with the primary wellbore below the junction.